pub const AVFMT_FLAG_CUSTOM_IO: i32 = 0x0080;Expand description
AVFMT_FLAG_CUSTOM_IO: the caller supplied the context’s pb, so libavformat
must not avio_close() it.
Hand-defined because bindgen’s AV_.* variable allowlist does not match
AVFMT_, the same reason AVFMT_NOFILE is defined here. The value is from
libavformat/avformat.h.